The toughest interview questions and the companies that ask them

WASHINGTON (WUSA9) -- Job interviews can be terrific, victorious events. Others can be the career equivalent of a root canal.

Glassdoor.com assembles information about companies like how much they pay for variety of postions, as well as tracking the interview process. It is out with a list of some of the toughest companies to interview at. Across the country, none are tougher than interviewing at consulting firm McKinsey & Company. Here's an example:

"How would you calculate the annual carbon emissions from electric versus gas vehicles in the EU?" YIKES!

A lot of these companies toss basically-impossible questions at candidates to get as sense of your thought process and problem-solving skills. A couple of toher examples;
-- "Name as many uses for a brick as you can in one minute."
-- "What kind of people do you dislike the most?

The worst question I ever got; did you have a happy childhood? Are you kidding me?

One rule to keep in mind if you do ever face one of these questions, don't get defensive. Just take it step by step and walk your way through it.